Electro-pneumatic digital interface

ABSTRACT

An electro-pneumatic digital interface device utilizing a low level electrical input signal to control an interrupter vane in a control port to a fluidic device.

United States Patent Allen 1451 June 6, 1972 [54] ELECTRO-PNEUMA'IIC DIGITAL v V R qg es Cited 7 INTERFACE UNITED STATES PATENTS 1 lnvenm Clmord Alien, Lexington, y- 3,304,049 2/1967 Wilkerson ..251/139 [73] A ig W i g Air Brake c p y wfl 3,513,866 Boothe et 137/8 1.5 merding, 3,24 0,219 3/1966 Dexter et al. 1 37/8 1.5 3,543,780 12/1970 Ahern ..137/s 1.5 [22] F1led: Apr. 28, 1970 [2!] Appl. Neg 32 697 Primary Examinerwilliam R. Cline Attorney-Ralph W. Mclntire, Jr.

us. (:1 .L ..137/81.5, 251/139 57 ABSTRACT ....Fl5c 3/08,Fl6k 31/02 I 3. [58] Field of Search ..137/s1.5; 251 /30, 139 elecm'pneummc dev'ce a level electrical input signal to control an interrupter vane in a control port to a fluidic device.

1 3 Claims 2 Drawing Figures ELECTRO-PNEUMATIC DIGITAL INTERFACE BACKGROUND OF THE INVENTION Industrial control systems presently in common use employ v a low-level electrical logic signal which requires interfacing to a fluid device in a fluid power system for controlling industrial machinery utilizing pneumatic or hydraulic cylinders and the like. This interfacing is usually done with solenoid valves limited to low-level signals that function inefficiently and at low speeds of response.

SUMMARY OF THE INVENTION According to the present invention, there is provided a rapid responsive electric to pneumatic interface device utilizing an interrupter vane to selectively control fluid flow in a control passage which monitors the continuity of fluid flow in a fluid jet, said interrupter vane being operably positioned responsive to a low level electric signal to an electro-magnet means to selectively position a metallic means attached to said vane.

DESCRIPTION Referring to the drawing, there is shown an interrupter vane I mounted on a flexible arm 2 which is rigidly secured to any secure mounting means 3 in a manner that the vane is normally a small distance away from a pole piece 4. The vane is of metallic or ferro-magnetic material with a non-magnetic shim 5 secured thereto to minimize residual magnet forces between the vane and the pole piece 4. Associated with the pole piece 4 is a winding 6 energized from a battery 7 when a switch 8 is closed. A passage 9 through the pole piece is located beneath the vane 1 in a manner to be closed off at one end when the arm 2 is flexed due to magnetic attraction between the vane and the pole piece during energization of the winding 6. The opposite end of the passage 9 is connected to a fluidic OR/NOR device to control the flow of fluid therethrough from a supply input 10 to one of two outputs 11 and 12. The OR/NOR devices of .FIG. 1 and 2 are of different modifications with FIG. 1 having auxiliary control ports 13 and 14 and FIG. 2 having an auxiliary control port 15, an over-ride port 16 and a bleed circuit or choke 17.

OPERATION When switch 8 is closed to energize the windings 6, the pole piece 4 will magnetically flex the arm 2 in the drawing the vane 1 to close the open end of passage 9. With the passage 9 closed, the jet flow through the OR/NOR gate will create a partial vacuum in said passage to cause the normal jet flow to output 11 to switch from output 1 1 to output 12 to effect a different control purpose. Thus, the normal jet flow to output 11 to serve a desired pneumatic control function is diverted to the output 12 to serve a different desired control function merely by closing the electric switch 8. Opening of the switch 8 permits the inherent spring force in the arm '2 to return the vane l to its open position. The non-magnetic shim 5 minimizes residual magnetic forces to permit rapid opening of the vane 1 from the pole piece 4. If for some reason the electric switching is inoperative, a small supply of fluid under pressure may be supplied by either of the auxiliary control ports 13 and 14 to divert the jet flow from the output 1 l to output 12.

In the modification shown in FIG. 2, some of the normal jet flow through the OR/NOR device from input 10 to output 11 is bled off through a choke 17 to the normally open control passage 9 in the pole piece 4. When said passage 915 open, the

flow of air through the choke 17 has no effect, however, when switch 8 is closed to effect closure of the passage 9 by the vane 1, the pressure from the choke 17 builds up in passage 9 and causes the jet flow through the OR/NOR device to be switched from output 1 1 to output 12 as desired to serve different pneumatic control functions. In the event of failure of vane operation for any reason, a small supply of fluid under pressure may be delivered via auxiliary control port 15 to divert the normal jet flow from output 11 to output 12. The over-ride port 16 may be supplied with fluid under pressure to over-ride the effect of closing the vane 1 if so desired.

Having now described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. An electric to pneumatic interface device for a fluid pressure system comprising:

a. a pure fluid digital control device having first and second outputs, and a control port subject to variation of fluid pressure to control pressurization of said first and second outputs,

b. electro-magnetic means including a magnetic core arranged with a selectively energized control winding, said core having a control passage extending therethrough communicated with said control port, and

. interrupter means comprising a flexible magnetic armature fixedly mounted at one end and selectively positionable with respect to said control passage to control fluid pressure therein in accordance with said armature opening said control port in one position responsive to one condition of energization of said winding and closing said control port in a second position responsive to a condition of energization of said winding opposite said one condition, said interrupter means further including a magnetic insulator carried by said armature when in said second position in spaced-apart relationship therewith sufficient to limit the residual magnetic force of attraction therebetween to a value less than the force of flexure of said armature.

2. The combination recited in claim 1 further characterized in that said control passage is subject to atmospheric pressure in said one position of said armature to effect one condition of pressurization of said first and second outputs, with flow of fluid pressure thereto being effective to establish subatmospheric pressure in said control passage in said second position of said armature to reverse the condition of pressurization of said first and second outputs. I

3. The combination recited in claim 1 further characterized in that said control passage is provided with a supply of fluid pressure which in said one position of said armature is communicated to atmosphere to efiect one condition of pressurization of said first and second outputs and in said second position is effective to pressurize said control passage to reverse the condition of pressurization of said first and second outputs.

1: k k k 

1. An electric to pneumatic interface device for a fluid pressure system comprising: a. a pure fluid digital control device having first and second outputs, and a control port subject to variation of fluid pressure to control pressurization of said first and second outputs, b. electro-magnetic means including a magnetic core arranged with a selectively energized control winding, said core having a control passage extending therethrough communicated with said control port, and c. interrupter means comprising a flexible magnetic armature fixedly mounted at one end and selectively positionable with respect to said control passage to control fluid pressure therein in accordance with said armature opening said control port in one position responsive to one condition of energization of said winding and closing said control port in a second position responsive to a condition of energization of said winding opposite said one condition, said interrupter means further including a magnetic insulator carried by said armature when in said second position in spaced-apart relationship therewith sufficient to limit the residual magnetic force of attraction therebetween to a value less than the force of flexure of said armature.
 2. The combination recited in claim 1 further characterized in that said control passage is subject to atmospheric pressure in said one position of said armature to effect one condition of pressurization of said first and second outputs, with flow of fluid pressure thereto being effective to establish subatmospheric pressure in said control passage in said second position of said armature to reverse the condition of pressurization of said first and second outputs.
 3. The combination recited in claim 1 further characterized in that said control passage is provided with a supply of fluid pressure which in said one position of said armature is communicated to atmosphere to effect one condition of pressurization of said first and second outputs and in said second position is effective to pressurize said control passage to reverse the condition of pressurization of said first and second outputs. 